Parent: Procelsterna (Blue-gray noddys)

└─ Procelsterna cerulea (Blue-gray noddy)

└─── Procelsterna cerulea cerulea

└─── Procelsterna cerulea murphyi

└─── Procelsterna cerulea nebouxi

└─── Procelsterna cerulea saxatilis

└─── Procelsterna cerulea teretirostris